@DeathByVisualStudio: How would you expect web-browser-based Office apps to cope with VBA macros that do things like interact with the FileSystemObject, or do WScript.Shell.Exec("malware.exe") ?
The only way I can see it working is insisting that users of the web-browser based Office app install an ActiveX component to run those VBA macros, but that sounds like it would be ( a) painful, (b) undermine a lot of the point of having an online product, (c) give Microsoft critics something different to complain about and (d) probably introduce all sorts of extra complexity, security problems and so on, all just so that VBA macros work in the web when you could instead just use Office 2013, connect to 365 and get the VBA macros through that instead.
That point is weak. In desktop version of Office you can always edit the spreadsheet with macros disabled (by not enabling it from the security bar). Why wouldn't WP version of office just assume macros are always disabled and allow us to edit the data?